[net,2/3] net_sched: fix a memory leak in cls_tcindex
diff mbox series

Message ID 20190211014731.23932-3-xiyou.wangcong@gmail.com
State Superseded
Delegated to: David Miller
Headers show
Series
  • net_sched: some fixes for cls_tcindex
Related show

Commit Message

Cong Wang Feb. 11, 2019, 1:47 a.m. UTC
When tcindex_destroy() destroys all the filter results in
the perfect hash table, it invokes the walker to delete
each of them. However, results with class==0 are skipped
in either tcindex_walk() or tcindex_delete(), which causes
a memory leak reported by kmemleak.

This patch fixes it by skipping the walker and directly
deleting these filter results so we don't miss any filter
result.

As a result of this change, we have to initialize exts->net
properly in tcindex_alloc_perfect_hash(). In net-next, we
need to evaluate whether we should initialize ->net in
tcf_exts_init() instead.

Cc: Jamal Hadi Salim <jhs@mojatatu.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 net/sched/cls_tcindex.c | 44 ++++++++++++++++++++++++++---------------
 1 file changed, 28 insertions(+), 16 deletions(-)

Comments

Cong Wang Feb. 11, 2019, 7:19 a.m. UTC | #1
On Sun, Feb 10, 2019 at 6:15 PM kbuild test robot <lkp@intel.com> wrote:
>
> Hi Cong,
>
> I love your patch! Yet something to improve:
>
> [auto build test ERROR on net/master]
>
> url:    https://github.com/0day-ci/linux/commits/Cong-Wang/net_sched-some-fixes-for-cls_tcindex/20190211-095057
> config: i386-randconfig-x002-201906 (attached as .config)
> compiler: gcc-8 (Debian 8.2.0-14) 8.2.0
> reproduce:
>         # save the attached .config to linux build tree
>         make ARCH=i386
>
> All errors (new ones prefixed by >>):
>
>    net/sched/cls_tcindex.c: In function 'tcindex_alloc_perfect_hash':
> >> net/sched/cls_tcindex.c:301:22: error: 'struct tcf_exts' has no member named 'net'
>       cp->perfect[i].exts.net = net;

Yeah, looks like I missed the CONFIG_CLS_ACT=n case.

Let me think about how to fix it properly.

Thanks!

Patch
diff mbox series

diff --git a/net/sched/cls_tcindex.c b/net/sched/cls_tcindex.c
index 14e6d80dd58e..6c3436e8436c 100644
--- a/net/sched/cls_tcindex.c
+++ b/net/sched/cls_tcindex.c
@@ -222,14 +222,6 @@  static int tcindex_delete(struct tcf_proto *tp, void *arg, bool *last,
 	return 0;
 }
 
-static int tcindex_destroy_element(struct tcf_proto *tp,
-				   void *arg, struct tcf_walker *walker)
-{
-	bool last;
-
-	return tcindex_delete(tp, arg, &last, NULL);
-}
-
 static void __tcindex_destroy(struct tcindex_data *p)
 {
 	kfree(p->perfect);
@@ -292,7 +284,7 @@  static void tcindex_free_perfect_hash(struct tcindex_data *cp)
 	kfree(cp->perfect);
 }
 
-static int tcindex_alloc_perfect_hash(struct tcindex_data *cp)
+static int tcindex_alloc_perfect_hash(struct net *net, struct tcindex_data *cp)
 {
 	int i, err = 0;
 
@@ -306,6 +298,7 @@  static int tcindex_alloc_perfect_hash(struct tcindex_data *cp)
 				    TCA_TCINDEX_ACT, TCA_TCINDEX_POLICE);
 		if (err < 0)
 			goto errout;
+		cp->perfect[i].exts.net = net;
 	}
 
 	return 0;
@@ -355,7 +348,7 @@  tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	if (p->perfect) {
 		int i;
 
-		if (tcindex_alloc_perfect_hash(cp) < 0)
+		if (tcindex_alloc_perfect_hash(net, cp) < 0)
 			goto errout;
 		for (i = 0; i < cp->hash; i++)
 			cp->perfect[i].res = p->perfect[i].res;
@@ -424,7 +417,7 @@  tcindex_set_parms(struct net *net, struct tcf_proto *tp, unsigned long base,
 	err = -ENOMEM;
 	if (!cp->perfect && !cp->h) {
 		if (valid_perfect_hash(cp)) {
-			if (tcindex_alloc_perfect_hash(cp) < 0)
+			if (tcindex_alloc_perfect_hash(net, cp) < 0)
 				goto errout_alloc;
 			balloc = 1;
 		} else {
@@ -585,13 +578,32 @@  static void tcindex_destroy(struct tcf_proto *tp,
 			    struct netlink_ext_ack *extack)
 {
 	struct tcindex_data *p = rtnl_dereference(tp->root);
-	struct tcf_walker walker;
+	int i;
 
 	pr_debug("tcindex_destroy(tp %p),p %p\n", tp, p);
-	walker.count = 0;
-	walker.skip = 0;
-	walker.fn = tcindex_destroy_element;
-	tcindex_walk(tp, &walker);
+
+	if (p->perfect) {
+		for (i = 0; i < p->hash; i++) {
+			struct tcindex_filter_result *r = p->perfect + i;
+
+			tcf_unbind_filter(tp, &r->res);
+			if (tcf_exts_get_net(&r->exts))
+				tcf_queue_work(&r->rwork,
+					       tcindex_destroy_rexts_work);
+			else
+				__tcindex_destroy_rexts(r);
+		}
+	}
+
+	for (i = 0; p->h && i < p->hash; i++) {
+		struct tcindex_filter *f, *next;
+		bool last;
+
+		for (f = rtnl_dereference(p->h[i]); f; f = next) {
+			next = rtnl_dereference(f->next);
+			tcindex_delete(tp, &f->result, &last, NULL);
+		}
+	}
 
 	if (maybe_get_net(p->net))
 		tcf_queue_work(&p->rwork, tcindex_destroy_work);